Process for producing impact resistant resins

Claim 1

A process for producing an impact resistant graft polymer which comprises: (a) forming an acid residue-containing copolymer (B) latex from a monomer group (b) consisting of at least one, α, β-unsaturated carboxylic acid selected from the group of acrylic acid, methacrylic acid, itaconic acid and crotonic acid; at least one alkyl acrylate having a C 1 -C 12 alkyl group and one or more copolymerizable monomers; by first, emulsion polymerizing a 5 to 90% by wt. portion of said monomer group (b) consisting of a monomer selected from the group of at least one alkyl acrylate having a C 1 -C 12 alkyl group, and at least one alkyl acrylate having a C 1 -C 12 alkyl group with one or more copolymerizable monomers which do not include the α, β-unsaturated carboxylic acid monomers; and then consecutively emulsion polymerizing the residual 95 to 10% by wt. portion of the monomer group (b) consisting of at least one of the α, β-unsaturated carboxylic acids selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid and crotonic acid, at least one of the alkyl acrylates selected from the group of C 1 -C 12 alkyl acrylates, and one or more of the copolymerizable monomers such that the formed copolymer (b) latex consists of 3 to 30% by wt. of said, α, β-unsaturated carboxylic acid monomer component, 97 to 35% by wt. of the alkyl acrylate monomer or monomers component, and 0 to 48% by wt. of the one or more of the copolymerizable monomer components; (b) adding 0.1 to 5 parts by weight of said copolymer (B) latex to 100 parts by weight of synthetic rubber (A) latex which has been adjusted to pH 7 or higher to obtain an agglomerated rubber (C) latex, wherein a larger portion is an elastomer constituting the synthetic rubber (A) and a smaller portion is the copolymer (B) latex incorporated therein, and wherein said agglomerated rubber (C) latex has a particle diameter of at least 0.2 microns; and then (c) emulsion polymerizing 93 to 30 parts by weight of grafting monomer (d) consisting of 30% by wt. or more of at least one monomer selected from the group consisting of styrene, acrylonitrile and methylmethacrylate and 70% by wt. or less of a monomer selected from the group consisting of styrene, α-methylstyrene, vinyltoluene, acrylonitrile, methacrylonitrile, alkyl methacrylates having a C 1 -C 12 alkyl group and alkyl acrylates having a C 1 -C 12 alkyl group copolymerizable therewith in the presence of 7 to 70 parts by weight of said agglomerated rubber (C) latex.